Prescription optical element for selected head mounted device

ABSTRACT

A distortion profile is based on user lens data and a selected optical-mechanical profile of a selected head mounted device. The user lens data is associated with prescription lenses worn by the user. A prescription optical layer is fabricated based on the distortion profile for the selected head mounted device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to U.S. non-provisional patent applicationsentitled, “Volumetric Depth Imaging for Lens Fit” and “PrescriptionOptical Element Based on Optical-Mechanical Profile,” filed the sameday.

BACKGROUND INFORMATION

Obtaining prescription eyeglasses typically includes taking an eyeglassprescription to an optician or other optical professional and selectingeye-glass frames to hold the corrective lenses. Some consumers who areswitching from one pair of eyeglasses to a new pair of eyeglasses reporta transition period (measured in minutes, days, or even weeks) to getused to the new eyeglasses. Some consumers also notice a transitionperiod when switching between two different eyeglasses that the consumeralready owns, even when the optical power of the two differenteyeglasses are the same.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting and non-exhaustive embodiments of the invention aredescribed with reference to the following figures, wherein likereference numerals refer to like parts throughout the various viewsunless otherwise specified.

FIG. 1 illustrates an example head mounted device that may includecorrective lenses that are fabricated based on a three-dimensional (3D)optical-mechanical fit profile of a user generated by a volumetric depthimage of the user wearing eyeglasses with corrective lenses, inaccordance with aspects of the disclosure.

FIG. 2 illustrates an example system that includes an optical coherencetomography (OCT) device that may be utilized to capture volumetric depthimages that include prescription lenses and the eyes of a wearer of theprescription lenses, in accordance with aspects of the disclosure.

FIGS. 3A-3B illustrate another example system that includes an opticalcoherence tomography (OCT) device that includes a scanner that may beutilized to capture volumetric depth images that include prescriptionlenses and the eyes of a wearer of the prescription lenses, inaccordance with aspects of the disclosure.

FIG. 4 illustrates a Fourier transform of an optical spectrum signalgenerating a depth signal, in accordance with aspects of the disclosure.

FIG. 5 illustrates an example scan of a person wearing eyeglassesincluding frames configured to hold prescription lenses in position onthe face of a wearer of the prescription lenses, in accordance withaspects of the disclosure.

FIGS. 6A-6B illustrate a slice of a volumetric depth image through ahorizontal plane, in accordance with aspects of the disclosure.

FIG. 7 illustrates a slice of a volumetric depth image through avertical plane, in accordance with aspects of the disclosure.

FIGS. 8A-8C illustrate various measurements from a volumetric depthimage, in accordance with aspects of the disclosure.

FIGS. 9A-9B illustrate an example meniscus prescription lens and anexample plano-concave lens having the same optical power, in accordancewith aspects of the disclosure.

FIG. 10 illustrates a process of generating a 3D optical-mechanical fitprofile for a user from a volumetric depth image of the wearer wearingtheir prescription eyeglasses, in accordance with aspects of thedisclosure.

FIG. 11 illustrates example processing logic that may be utilized toexecute the process of FIG. 10 , in accordance with aspects of thedisclosure.

FIG. 12 illustrates an example prescription optical element for a headmounted display that includes a plano-concave optical layer and anoptical element, in accordance with aspects of the disclosure.

FIGS. 13A-13C illustrate a system for fabricating a plano-concaveoptical layer based on an optical-mechanical fit profile, in accordancewith aspects of the disclosure.

FIG. 14 illustrates a bonding process of fabricating a prescriptionoptical element, in accordance with aspects of the disclosure.

FIGS. 15A-15C illustrate a system for generating lens measurement data,in accordance with aspects of the disclosure.

FIG. 16 illustrates different frames of head mounted devices, inaccordance with aspects of the disclosure.

FIG. 17 illustrates a process of fabricating a prescription opticalelement for a selected head mounted device that may reduce a transitiontime experienced by a user switching between eyeglasses and the headmounted device, in accordance with aspects of the disclosure.

FIG. 18 illustrates an example fabrication process of fabricating aprescription optical element for a selected head mounted device that mayreduce a transition time experienced by a user switching betweeneyeglasses and the head mounted device, in accordance with aspects ofthe disclosure.

FIGS. 19A-19C illustrate see-through light outputs from as-builtprescription optical elements and an example measured distortionprofile, in accordance with aspects of the disclosure.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth toprovide a thorough understanding of the embodiments. One skilled in therelevant art will recognize, however, that the techniques describedherein can be practiced without one or more of the specific details, orwith other methods, components, materials, etc. In other instances,well-known structures, materials, or operations are not shown ordescribed in detail to avoid obscuring certain aspects.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment of the present invention. Thus, theappearances of the phrases “in one embodiment” or “in an embodiment” invarious places throughout this specification are not necessarily allreferring to the same embodiment. Furthermore, the particular features,structures, or characteristics may be combined in any suitable manner inone or more embodiments.

Embodiments of this disclosure include generating a distortion profilebased on user lens data and a selected optical-mechanical profile of aselected head mounted device. The user lens data is associated withprescription lenses worn by the user. A prescription optical layer isfabricated based on the distortion profile for the selected head mounteddevice.

Literature associated with the field of optometry suggests thatdifferences in lenses and frames may account for a transition periodwhen a person switches between corrective lenses. For example,differences in eye-relief, interpupillary distance (IPD), frame tiltangle, refractive material of lenses, residual aberrations, size oflenses, and/or base curve may contribute to a transition period where aperson gets used to new corrective lenses. In one particular context, aprescription optical layer of this disclosure has a same or similardistortion profile as the prescription lenses in eyeglasses worn by theuser so that a transition period is reduced between a person switchingfrom prescription eyeglasses and augmented reality (AR) glasses. Theseand other embodiments are described in more detail in connection withFIGS. 1-19C.

FIG. 1 illustrates an example head mounted device 100 that may includecorrective lenses 121 that are fabricated based on a 3Doptical-mechanical fit profile of a user generated by a volumetric depthimage of the user wearing eyeglasses with corrective lenses, inaccordance with aspects of the disclosure. Head mounted device 100 maybe considered an AR or mixed reality (MR) head mounted display, in someaspects of the disclosure. In some aspects, head mounted device 100 doesnot necessarily include a display but does include electronics of somekind such as one or more cameras, speakers, eye-tracking sensor modules,other sensors, processors, and/or memory.

In FIG. 1 , example head mounted device 100 includes frame 114 coupledto arms 111A and 111B. Lenses 121A and 121B are mounted to frame 114.Lenses 121 may include optical power matched to a particular wearer ofhead mounted device 100. The illustrated head mounted device 100 isconfigured to be worn on or about a head of a user.

Each lens 121 may optionally include a waveguide 150 to direct imagelight generated by a display 130 to an eyebox area for viewing by awearer of head mounted device 100. Display 130 may include an LCD, anorganic light emitting diode (OLED) display, micro-LED display, quantumdot display, pico-projector, or liquid crystal on silicon (LCOS) displayfor directing image light to a wearer of head mounted device 100.

The frame 114 and arms 111 of the head mounted device 100 may includesupporting hardware of head mounted device 100. Head mounted device 100may include any of processing logic, wired and/or wireless datainterface for sending and receiving data, graphic processors, and one ormore memories for storing data and computer-executable instructions. Inone embodiment, head mounted device 100 may be configured to receivewired power. In one embodiment, head mounted device 100 is configured tobe powered by one or more batteries. In one embodiment, head mounteddevice 100 may be configured to receive wired data including video datavia a wired communication channel. In one embodiment, head mounteddevice 100 is configured to receive wireless data including video datavia a wireless communication channel.

Lenses 121 may appear transparent to a user to facilitate augmentedreality or mixed reality where a user can view scene light from theenvironment around her while also receiving image light directed to hereye(s) by waveguide(s) 150. Consequently, lenses 121 may be considered(or include) an optical combiner. In some embodiments, image light isonly directed into one eye of the wearer of head mounted device 100. Inan embodiment, both displays 130A and 130B are included to direct imagelight into waveguides 150A and 150B, respectively.

FIG. 2 illustrates an example system 200 that includes an opticalcoherence tomography (OCT) device 201 that may be utilized to capturevolumetric depth images that include prescription lenses and the eyes ofa wearer of the prescription lenses, in accordance with aspects of thedisclosure. The illustrated OCT system 200 is a Fourier-domain OCTsystem rather than a time-domain OCT system. In time-domain OCT systems,a reference mirror of the reference arm is moved axially during thesignal acquisition whereas the reference mirror is kept stationary inFourier-domain OCT systems. Fourier-domain OCT system 200 may be aspectral-domain OCT system or a swept-source OCT system. When system 200is a spectral-domain OCT system, light source 210 includes a broadbandlight source and detector 290 includes a spectrometer. When system 200is a swept-source OCT system, light source 210 includes a swept lasersource and detector 290 includes a photodetector OCT system 200 is oneexample of an imaging system that may capture volumetric depth imagesthat include prescription lenses and the eyes of the wearer of theprescription lenses. A volumetric depth image may be generated by atime-of-flight imaging system, a Light Detection and Ranging (LIDAR)imaging system, or focused ultrasound imaging, in accordance with otherembodiments of the disclosure.

System 200 includes OCT device 201 that includes a light source 210, areference arm 203, a sample arm 207, a fiber coupler 220, a detector290, and OCT logic 295. System 200 also includes processing logic 297that includes memory 298. In some embodiments, memory 298 may beexternal to processing logic 297 and processing logic 297 is configuredto read and/or write to the external memory.

OCT device 201 is configured to capture a volumetric depth image 296that includes imaging of prescription lens 270 and at least a portion ofeye 250. In addition to the eye 250 of a wearer of prescription lens270, the volumetric depth image 296 may also include portions of theface of a wearer of prescription lens 270 such that volumetric depthimage 296 captures a three-dimensional image of the prescription lens270 with respect to the face and/or eye of the wearer of prescriptionlens 270.

Light source 210 may include a non-visible light source that illuminatesoptical fiber 223 with illumination light that encounters fiber coupler220. Non-visible light may be defined as light having wavelengths thatare outside the visible light range, such as ultraviolet light andinfrared light. In aspects of this disclosure, visible light may bedefined as having a wavelength range of approximately 380 nm-700 nm.Infrared light having a wavelength range of approximately 700 nm-1 mmincludes near-infrared light. In aspects of this disclosure,near-infrared light may be defined as having a wavelength range ofapproximately 700 nm-1.4 μm. Using infrared light allows for shallowpenetration into sample such that a depth below skin or eyes may beimaged. In an example spectral-domain OCT embodiment, light source 210is a broadband light source emitting non-visible illumination lightcentered around 840 nm. In an example swept-source OCT embodiment, lightsource 210 is a swept-source laser. Fiber coupler 220 may be a 2×2 fibercoupler that splits the illumination light between the reference arm 203and sample arm 207. Reference arm 203 may include optical elements 235and 237 to focus the reference light 204 to reference mirror 260. Samplearm 207 may include optical elements 245 and 247 to focus the samplelight 208 to the sample (the prescription lens 270 and eye 250, in theillustrated example). Reference mirror 260 may be positioned at a sameor similar optical pathlength as the sample to be imaged.

Backscattered light from the prescription lens 270 and eye 250 or face(not illustrated) interfere at fiber coupler 220 to generate opticalinterference signal 211 that is received by detector 290. Detector 290generates an optical spectrum signal 213 from the optical interferencesignal 211. Surfaces of the sample that backscatter a significant amountof light will cause interferences of greater intensity. In an examplespectral-domain OCT embodiment, detector 290 is a 250 kHz spectrometer.In an example swept-source OCT embodiment, detector 290 is a photodiode.

FIG. 4 illustrates that a Fourier Transform 423 of an optical spectrumsignal 413 generates a depth profile 440 and that the peaks 441 and 443of depth profile 440 are representative of backscattering surfaces ofthe sample. In FIG. 4 , peak 441 may be generated by a backscattering ofa first surface of prescription lens 270 and peak 443 may be generatedby a backscattering of a second surface of prescription lens 270, forexample. Other surfaces of the sample such as the cornea, limbus,iris/pupil, and/or lens may also generate backscattered light thatcontributes to a depth profile. Thus, a depth profile may be generatedfrom each optical spectrum signal (e.g. 213) generated by an OCT device(e.g. OCT device 201).

FIG. 5 illustrates an example scan 500 of a person wearing eyeglassesincluding frames 514 configured to hold prescription lenses 521A and521B in position on the face of a wearer of the prescription lenses 521Aand 521B. In a scan 500 to acquire a volumetric depth image, a pluralityof depth profiles 523 are acquired to generate a volumetric depth imageover example scan field 540. Example scan field 540 includes bothprescription lenses 521A and 521B and eyes 250A and 250B, although thescan field in some embodiments may be more or less than scan field 540in FIG. 5 . Eyes 250 includes iris 551 and pupil 522, in FIG. 5 .Capturing a volumetric depth image may include scanning lines of depthprofiles 523 across scan field 540. Example line 521 includestwenty-four depth profiles 523, for example. Some lines (e.g. line 521)may include 250 depth profiles 523 and 500 lines may be captured in ascan 500 going from left to right. Consequently, generating a volumetricdepth image (e.g. volumetric depth image 296) may include capturing125,000 depth profiles 523, in that example. Capturing each depthprofile 523 may take approximately 4 μs. Other lateral positions andscan rates may also be utilized. OCT logic 295 may receive an opticalspectrum signal 213 for each depth profile 523, perform a FourierTransform on each received optical spectrum signal 213 to generate adepth profile for each optical spectrum signal and then aggregate thedepth profiles to generate a volumetric depth image 296 of the entirescan field. In FIG. 2 , the volumetric depth image 296 is provided toprocessing logic 297 for further processing.

FIG. 6A illustrates a slice 600 of a volumetric depth image through ahorizontal plane indicated by dashed-line 580 of FIG. 5 , in accordancewith aspects of the disclosure. Slice 600 may be generated by aplurality of depth profiles 623. Slice 600 shows that eyeglasses 610include arms 611A and 611B attached to glasses frame 614 securingprescription lenses 621A and 621B. Prescription lens 621A corrects thevision of eye 650A of wearer 601 and prescription lens 621B corrects thevision of eye 650B of wearer 601.

FIG. 6B illustrates a zoomed-in portion 699 of slice 600, in accordancewith aspects of the disclosure. Prescription lens 621A of eyeglasses 610includes a front surface 622A and a back surface 624A. An eye-reliefmeasurement 607 may be determined from a front surface 641 of a corneaof eye 650A and a point on the back surface 624A of lens 621A. The frontsurface 641 of the cornea, the back surface 642 of the cornea, the frontsurface 661 of eye lens 660, the back surface 662 of eye lens 660, andiris 670 may also generate backscattered light that is significantenough to be imaged in a volumetric depth image. Other features of eye650A may also generate backscattered light that can be imaged by an OCTdevice such as OCT device 201. FIG. 6B illustrates that the skin aroundthe eye and the nose of wearer 601 may also generate backscattered lightthat can be imaged by an OCT device. The pupil 675 of eye 650A may bedetermined by the space between iris 670. Although not shown in FIG. 6B,the retina of eye 650A may also be included in the volumetric depthimage.

FIG. 7 illustrates a slice 700 of a volumetric depth image through avertical plane indicated by dashed-line 590 of FIG. 5 , in accordancewith aspects of the disclosure. Slice 700 may be generated by aplurality of depth profiles 723. Slice 700 includes an upper eyelid anda lower eyelid. The volumetric depth image may even include eyelashes777.

Slice 700 and slice 600 illustrate that a volumetric depth image caninclude a full three-dimensional image of prescription lenses and theeyes and face of a wearer 601 of eyeglasses 610. Thus, lens-to-eye datathat includes measurements of the prescription lens(es) with respect tothe eye 650 can be generated. FIGS. 6B and 7 show eye-relief measurement607 as one example of lens-to-eye data. In addition, a base curve of thefront surface 622A and a back curve of back surface 624A of prescriptionlens 621A may also be generated since lens 621A is fully imaged inthree-dimensions in the volumetric depth image. For the purposes of thedisclosure, the term “base curve” is associated with the profile of thefront surface (e.g. 622A) of a prescription lens and the term “backcurve” is associated with the profile of the back surface (e.g. 624A) ofthe prescription lens.

FIG. 8A illustrates that when both eyes 650A and 650B are included in avolumetric depth image, an interpupillary distance (IPD) 817 can also bederived from the distance between a first pupil 675A of eye 650A and asecond pupil 675B of eye 650B. A pupil size (e.g. diameter) of pupils675 may also be measured from a volumetric depth image.

FIG. 8B illustrates that an eye-relief measurement 807 from a volumetricdepth image can be measured from any point of the cornea of the eye toany point on the back surface of lens 821. FIG. 8C illustrates a frametilt angle 809 from a volumetric depth image can be measured to derivethe angle at which glasses frames (not illustrated hold the prescriptionlens(es) 821 with respect to a vertical plane.

FIG. 3A illustrates another example system 300 that includes an opticalcoherence tomography (OCT) device 301 that may be utilized to capturevolumetric depth images that include prescription lenses and the eyes ofa wearer of the prescription lenses, in accordance with aspects of thedisclosure. The illustrated OCT system 300 is a Fourier-domain OCTsystem similar to OCT system 200 where a two-dimensional scanner 309 anda scan or eyepiece lens 347 has been included in sample arm 307. Scanner309 may be implemented with a micro-electro-mechanical systems (MEMS)micro-mirror to quickly direct light 308 to different regions of a scanfield (e.g. scan field 540) of eye 250.

FIG. 3B illustrates an example scan lens 357 configured to distributelight 308 from an exit point 353 of scanner 309 to a particular focuspoint for a particular depth profile. In other words, scanner 309 maydirect light 308 at a variety of angles when capturing different depthprofiles 523 to cover the scan field and scan lens 357 is configured todirect the light 308 to the sample and focus backscattered light fromthe sample back to scanner 309 to be reflected back to fiber coupler 220via the optical fiber 323.

OCT device 301 is configured to capture a volumetric depth image 396that includes prescription lens 270 and at least a portion of eye 250.In addition to the eye 250 of a wearer of prescription lens 270, thevolumetric depth image 396 may also include portions of the face of awearer of prescription lens 270 such that volumetric depth image 396captures a three-dimensional image of the prescription lens 270 withrespect to the face and/or eye 250 of the wearer of prescription lens270. System 300 also includes processing logic 397 that includes memory398. In some embodiments, memory 398 may be external to processing logic397 and processing logic 397 is configured to read and/or write to theexternal memory.

Backscattered light from the prescription lens 270 and eye 250 or face(not illustrated) interfere at fiber coupler 220 to generate opticalinterference signal 311 that is received by detector 290. Detector 290generates an optical spectrum signal 313 from the optical interferencesignal 311. A plurality of optical spectrum signals 313 for a pluralityof depth profiles may be aggregated to generate volumetric depth image396, in FIG. 3A.

Volumetric depth images (e.g. images 296 or 396) provide a dense 3Dimage of the eye and/or face of a wearer with respect to prescriptionlenses. This allows for a reconstruction of the prescription surfaceprofile of the prescription lens such that the optical power of theprescription lens, the base curve, and the back curve of theprescription lens can be known.

While FIGS. 2-3B illustrate example embodiments of OCT systems forgenerating volumetric depth images, other OCT systems may also bedeployed to capture volumetric depth images. For example, an OCT systemwith multiple spectrometers and/or reference arms may be used wheredifferent spectrometers and/or reference arms are configured to measuredifferent depths to increase the depth of the volumetric depth image bystitching together images of different imaging depths. An OCT system mayalso include multiple scan lenses to increase a field of view (FOV) ofthe OCT system. In some embodiments, multiple scanner pairs of an OCTsystem are activated in parallel where each of the scanner pairs isconfigured to image different FOVs of different parts of the face inorder to reduce an acquisition time of the volumetric depth image bystitching the different captured FOVs together as one volumetric depthimage. An OCT system that includes a single axis (line) galvo scannermay be utilized to increase the acquisition speed of volumetric depthimage(s), in some embodiments. In some embodiments, a full-field OCTsystem may be used.

FIG. 9A illustrates an example meniscus prescription lens 905 foreyeglasses having an optical power of −4.00 Diopter where the base curveof the front surface 906 has a +5.00 curve and the back curve of theback surface 907 has a −9.00 curve. FIG. 9B illustrates an exampleplano-concave lens 915 having the same −4.00 Diopter optical powergenerated by a plano front surface 916 having a 0.00 curve and a concaveback surface 917 having a −4.00 curve. Meniscus prescription lens 905 iscommonly used in prescription lenses for conventional eyeglasses whileplano-concave lens 915 may be utilized for use in a head mounted devicethat includes a prescription lens so that the plano front surface 916 ofplano-concave lens 915 can be bonded to a planar surface of additionaloptical layers (e.g. eye-tracking layer and/or display layer) of a headmounted device such as an AR head mounted display (HMD). Yet, althoughlens 905 and 915 have the same optical power, users may experiencediscomfort during a transition time between switching between lens 905and 915. The transition time may be attributed to distortion changes inthe lens itself, residual aberrations, or a fitting mismatch. Theresidual aberrations may be attributed to uncorrected lower and higherorder aberrations in the lenses and the fitting mismatch may beattributed to a decentration of the lenses (housed in glasses) on thewearer's face that may result in unwanted distortion or image shift.

Thus, having volumetric depth images that provide a dense 3D image ofthe eye or face of a wearer with respect to prescription lenses mayallow a three-dimensional (3D) optical-mechanical fit profile to begenerated for a wearer of glasses and the 3D optical-mechanical fitprofile can be used to adjust a configuration of a head mounted devicespecifically for the wearer, based on a volumetric depth image of thewearer wearing their prescription lenses of their eyeglasses. Theadjustment to the head mounted device based on the 3D optical-mechanicalfit profile may assist in reducing or eliminating a transition timebetween a wearer's conventional prescription eyeglasses and a headmounted device that includes corrective lenses.

FIG. 10 illustrates a process 1000 of generating 3D optical-mechanicalfit profile for a user from a volumetric depth image of the wearerwearing their prescription eyeglasses, in accordance with aspects of thedisclosure. The order in which some or all of the process blocks appearin process 1000 should not be deemed limiting. Rather, one of ordinaryskill in the art having the benefit of the present disclosure willunderstand that some of the process blocks may be executed in a varietyof orders not illustrated, or even in parallel.

In process block 1005, a volumetric depth image (e.g. volumetric depthimage 296 or 396) is captured. The volumetric depth image includes afront surface of a prescription lens, a back surface of the prescriptionlens, and a cornea of an eye of a wearer of the prescription lens. Thevolumetric depth image may also include a limbus, an iris/pupildefinition, a retina mapping, a definition of an anterior chamber of theeye, and/or a lens of the eye of the wearer of the prescription lens. Inan embodiment, the volumetric depth image also includes a secondprescription lens and a second eye of the wearer of the secondprescription lens.

In process block 1010, lens-to-eye data is determined from thevolumetric depth image. The lens-to-eye data includes measurements ofthe prescription lens with respect to the eye of the wearer. Thelens-to-eye data may include a base curve of the front surface (e.g.622A) of the prescription lens and a back curve of the back surface(e.g. 624A) of the prescription lens. The lens-to-eye data may includean eye-relief measurement. The lens-to-eye data may include aninterpupillary distance (IPD) between a first pupil of a first eye and asecond pupil of a second eye, when the volumetric depth image includestwo eyes. The lens-to-eye data may include at least one of eye-reliefdistance, pupil size of one or both eyes, frame tilt angle, framefitting height, or corneal topography of the cornea of one or both eyes.The eye-relief distance may be defined from the back surface of theprescription lens to the cornea of the eye. The frame tilt angle maymeasure an angle of a glasses frame that holds the prescription lenswith respect to a vertical plane.

In process block 1015, a three-dimensional (3D) optical-mechanical fitprofile is generated for the wearer based on the lens-to-eye data andbased on the volumetric depth image. Therefore, the 3Doptical-mechanical fit profile may include a 3D model of theprescription lenses with respect to the eye and/or face of a user andrelevant lens-to-eye data. The 3D optical-mechanical fit profile for aparticular user may be used to determine a compatibility with aparticular head mounted device for a user. For example, an IPD of a usermay determine a size of a head mounted device that would be mostcompatible with the user. The 3D optical-mechanical fit profile for aparticular user may be used to adjust a configuration of a head mounteddevice for a user to reduce or eliminate a transition period betweenusing eyeglasses and a head mounted device that includes correctivelenses specific to the user.

In embodiments of process 1000, capturing the volumetric depth imageincludes capturing a plurality of optical spectrum signals with anoptical coherence tomography (OCT) system (e.g. system 200 or 300) wherethe optical spectrum signals in the plurality are generated bybackscattered light from the front surface of the prescription lens, theback surface of the prescription lens, and the cornea of the eye. TheOCT system may be a Fourier-domain OCT system including a light sourceto illuminate the eye, the prescription lens, and a reference mirror ofthe Fourier-domain OCT system. The volumetric depth image is generatedby performing a Fourier Transform of each of the optical spectrumsignals to generate depth profiles that are aggregated together as thevolumetric depth image, in some embodiments.

In some embodiments of process 1000, the volumetric depth image isgenerated by one of time-of-flight imaging, Light Detection and Ranging(LIDAR) imaging, or focused ultrasound imaging.

Processing logic 297 or processing logic 397 may be configured toexecute process 1000. FIG. 11 illustrates example processing logic 1197that may be utilized as processing logic 297 or 397 to execute process1000, in accordance with aspects of the disclosure. Processing logic1197 includes lens-to-eye data engine 1105, optical-mechanical fitprofile engine 1115, distortion profile engine 1125, and user profilemodule 1135. Processing logic 1197 also includes memory 1198. In someembodiments, memory 1198 may be external to processing logic 1197 andprocessing logic 1197 is configured to read and/or write to the externalmemory.

Lens-to-eye data engine 1105 of processing logic 1197 is configured toreceive a volumetric depth image 1196. Lens-to-eye data engine 1105 isconfigured to determine lens-to-eye data 1107 from volumetric depthimage 1196. The lens-to-eye data 1107 includes measurements of theprescription lens with respect to the eye of the wearer. The lens-to-eyedata 1107 may include a base curve of the front surface (e.g. 622A) ofthe prescription lens and a back curve of the back surface (e.g. 624A)of the prescription lens. The lens-to-eye data 1107 may include aneye-relief measurement. The lens-to-eye data 1107 may include aninterpupillary distance (IPD) between a first pupil of a first eye and asecond pupil of a second eye, when the volumetric depth image includestwo eyes. The lens-to-eye data 1107 may include at least one ofeye-relief distance, pupil size of one or both eyes, frame tilt angle,or corneal topography of the cornea of one or both eyes. Lens-to-eyedata engine 1105 may use conventional image processing techniques todetermine the lens-to-eye data 1107 such as comparing features in thevolumetric depth image 1196 to a size of the image that is known or anobject in the volumetric depth image 1196 that has a known size.

Optical-mechanical fit profile engine 1115 is configured to receivevolumetric depth image 1196 and lens-to-eye data 1107 and generate 3Doptical-mechanical fit profile 1117 based on lens-to-eye data 1107 andvolumetric depth image 1196. Optical-mechanical fit profile engine 1115may be configured to augment volumetric depth image 1196 withlens-to-eye data 1107 to generate 3D optical-mechanical fit profile1117, in some embodiments.

User profile module 1135 is configured to receive user data 1151 that isassociated with volumetric depth image 1196. User data 1151 may includethe name or username for the person that was imaged wearing theirprescription lenses to generate volumetric depth image 1196. Userprofile module 1135 may link 3D optical-mechanical fit profile 1117 withuser data 1151 to generate user optical profile 1137. User opticalprofile 1137 may then be stored to memory 1198, uploaded to a clouddatabase, or provided to a network or another device. User opticalprofile 1137 may be encrypted for privacy protection.

Distortion profile engine 1125 is optionally included in processinglogic 1197 and may be configured to receive 3D optical-mechanical fitprofile 1117. Distortion profile engine 1125 may be configured togenerate a distortion profile 1127 from 3D optical-mechanical fitprofile 1117. Distortion profile engine 1125 may determine a visualacuity or a Modulation Transfer Function (MTF) and/or a point spreadfunction (PSF) of the prescription lens(es) of 3D optical-mechanical fitprofile 1117, in some embodiments, and include that MTF and/or PSF indistortion profile 1127. The MTF and/or PSF may be determined from theprescription lenses imaged in volumetric depth image 1196. It may beadvantageous to fabricate a plano-concave lens (e.g. 915) for a headmounted device that includes similar see-through optical performance ofthe existing prescription lenses to reduce or eliminate a transitionperiod between switching between eyeglasses and the head mounted device.Thus, the plano-concave lens may be fabricated with the same or similardistortion profile as the user's existing prescription lenses, asmeasured by visual acuity, MTF and/or PSF. The same or similardistortion profile may be designed for the plano-concave lens by opticaldesign software in order to match the distortion profile of the existingprescription lenses.

When distortion profile engine 1125 is included in processing logic1197, distortion profile 1127 may be provided to user profile module1135 and user profile module 1135 may link distortion profile 1127 withuser data 1151 to generate user optical profile 1137. User opticalprofile 1137 may then be stored to memory 1198, uploaded to a clouddatabase, or provided to a network or another device. In thisembodiment, distortion profile 1127 may include the data of 3Doptical-mechanical fit profile 1117.

FIG. 12 illustrates an example prescription optical element 1200 for ahead mounted device that includes a plano-concave optical layer 1210 andan optical element 1220, in accordance with aspects of the disclosure.Example prescription optical element 1200 may be used as a correctivelens in a head mounted device such as head mounted device 100. Exampleoptical element 1220 includes an eye-tracking layer 1221, a displaylayer 1223, and base curve layer 1225. Base curve layer 1225 andplano-concave optical layer 1210 are refractive elements, in FIG. 12 .Display layer 1223 directs display light 1293 to an eyebox area topresent images to an eyebox area so that an eye of a user can viewimages included in display light 1293. Display layer 1223 is disposedbetween base curve 1227 and plano-concave optical layer 1210.Eye-tracking layer 1221 may illuminate the eyebox area with non-visiblelight 1291 (e.g. infrared light) emitted from an illumination layer foreye-tracking purposes. In some embodiments, eye-tracking layer 1221 mayalso include a combiner layer to receive reflections of the non-visiblelight from the eyebox area and redirect the reflections to a camera forimaging the eyebox area. Base curve layer 1225 includes a base curve1227 and plano-concave optical layer 1210 includes concave-side 1211.The curvature of concave-side 1211 and base curve 1227 provide theoptical power for prescription optical element 1200 for real-world scenelight 1299 that propagates through prescription optical element 1200.

FIG. 13A illustrates a system 1300 for fabricating a plano-concaveoptical layer based on an optical-mechanical fit profile, in accordancewith aspects of the disclosure. System 1300 includes processing logic1391 and lens shaping apparatus 1350. Lens shaping apparatus 1350 isconfigured to fabricate plano-concave optical layer 1210 on platform1340. The illustrated lens shaping apparatus 1350 is configured as a 3Dprinter that fabricates plano-concave optical layer 1210 in an additivefabrication process by building up plano-concave optical layer 1210 witha 3D printing material such as resin provided through nozzle 1315. Theresin may be optical resin that is transparent. Lens shaping apparatus1350 includes a stage 1356 for moving nozzle 1315 in three dimensions.

Processing logic 1391 is configured to receive optical-mechanical fitprofile 1357. User optical profile 1137 may be provided to processinglogic 1391 as optical-mechanical fit profile 1357. Optical-mechanicalfit profile 1357 may be received from a cloud database in someembodiments. Optical-mechanical fit profile 1357 may include a mappingof prescription lenses with respect to a face of a wearer of theprescription lenses. Optical-mechanical fit profile 1357 may include aninterpupillary distance (IPD) between a first pupil of a first eye ofthe wearer and a second pupil of a second eye of the wearer of theprescription lenses. Optical-mechanical fit profile 1357 may include adistortion profile and an optical power of the prescription lenses.Processing logic 1391 is coupled to drive lens shaping apparatus 1350 tofabricate plano-concave optical layer 1210 based on optical-mechanicalfit profile 1357. Plano-concave optical layer 1210 may then be coupledto optical element 1220 to form prescription optical element 1200 for ahead mounted device.

As discussed briefly above, a base curve 1227 of optical element 1220may be different from a base curve of prescription lenses (e.g. basecurve of front surface 906) worn by a user in conventional eyeglasses.The curvature of concave-side 1211 of plano-concave optical layer 1210and the base curve 1227 combine to provide the same optical power as theuser's conventional prescription lenses so that that scene light fromthe user's ambient environment will be focused for their eye(s). Basecurve 1227 may have a nominal base curve of +0.5 Diopters, in oneexample. Other base curves may also be used. Additionally, plano-concaveoptical layer 1210 may be fabricated so prescription optical element1200 has a matched distortion profile that is substantially similar tothe distortion profile of the conventional prescription lenses worn bythe user to reduce an adaptation time of switching between theconventional prescription lenses and the head mounted device thatincludes prescription optical element 1200. The head mounted device isan AR HMD, in some embodiments. Plano-concave optical layer 1210 mayalso be fabricated so two prescription optical elements 1200 have thesame IPD as the user's eyeglasses, when taking into account where thetwo prescription optical elements will be situated within a frame (e.g.114) of a head mounted device.

The distortion profile of the prescription lenses may be the visualacuity, MTF, and/or PSF of the prescription lenses that are then matchedto the prescription optical element 1200. The see-through opticalproperties of display layer 1223 (if included in prescription opticalelement 1200) and/or the see-through optical properties of eye-trackinglayer 1221 (if included in prescription optical element 1200) may beaccounted for when fabricating plano-concave optical layer 1210 suchthat prescription optical element 1200 has a matched distortion profilethat is substantially similar to the distortion profile of theconventional prescription lenses in the eyeglasses worn by the user.

FIG. 13B illustrates an embodiment where optical resin 1312 encapsulatesinfrared illuminators 1322 of illumination layer 1321, in accordancewith aspects of the disclosure. Infrared illuminators 1322 may includean array of infrared light emitting diodes (LEDs) or an array ofinfrared vertical-cavity surface emitting lasers (VCSELs) configured toilluminate an eyebox area with infrared light. Fabricating plano-concaveoptical layer 1310 by encapsulating infrared illuminators 1322 mayeliminate additional process steps in fabricating a prescription opticalelement 1349 because 3D printing plano-concave optical layer 1310 ontoillumination layer 1321 may eliminate a separate encapsulation processand a bonding process that bonds a plano-concave optical layer (e.g.1210) to an optical element such as optical element 1220.

FIG. 13C illustrates a lens shaping apparatus 1351 that may be utilizedin place of lens shaping apparatus 1350 to generate a plano-concaveoptical layer, in accordance with aspects of the disclosure. Lensshaping apparatus 1351 includes a bit 1317 to fabricate plano-concaveoptical layer 1360 held by platform 1390 using a subtractive fabricationprocess. Plano-concave optical layer 1360 may be milled from an opticalquality refractive material. Lens shaping apparatus 1351 includes astage 1358 for moving bit 1317 in three dimensions. Lens shapingapparatus 1351 may be configured to facilitate a diamond turningfabrication process, in some embodiments. A plano-concave optical layermay also be fabricated utilizing a casting or molding process (notillustrated).

FIG. 14 illustrates a bonding process of fabricating a prescriptionoptical element, in accordance with aspects of the disclosure. In FIG.14 , a plano-side 1412 of plano-concave optical layer 1410 is bonded toa planar surface of eye-tracking layer 1221 of optical element 1220.

FIG. 15A illustrates a system 1500 for generating lens measurement data1599, in accordance with aspects of the disclosure. System 1500 may beused as an alternative to systems 200 and 300 to generate lens data fromprescription lenses of a user's prescription eyeglasses, even though thelens data may not include a 3D mapping of the prescription lenses withrespect to the user's eye and/or face. System 1500 may be configured tomeasure the see-through quality of prescription lenses 1531 ofeyeglasses 1530 including distortion, MTF, and/or PSF for bothstationary and rotated perspectives.

System 1500 includes a display 1557 that may be coupled with a linearstage (not illustrated) that moves display 1557 along axis 1583 so thatdisplay 1557 can be brought closer to eyeglasses 1530 or moved fartheraway from eyeglasses 1530 during a characterization procedure of lenses1531. Processing logic 1597 may be configured to drive the linear stageto move display 1557 along axis 1583 with input/output X3. Processinglogic 1597 is configured to drive different images onto display 1557 forpurposes of analyzing prescription lenses 1531A and 1531B. Display 1557may be an 850 nm LED display emitting near-infrared light, in someembodiments.

Optical sensor 1555 is coupled to provide image signals 1556 toprocessing logic 1597 where the optical sensor 1555 is configured toimage display 1557. Optical sensor 1555 serves as a model eye in placeof where a user's eye might be positioned. Optical sensor 1555 may be acomplimentary metal-oxide semiconductor (CMOS) image sensor and imagesignals 1556 may include images captured by the CMOS image sensor.Eyeglasses 1530 may be secured to a rotation stage (not specificallyillustrated) that rotates along rotation axis 1581. Processing logic1597 may be configured to drive the rotation stage to move eyeglasses1530 along rotation axis 1581 with input/output X2. Eyeglasses 1530 mayalso be coupled to a tilting mechanism (not specifically illustrated)that tilts eyeglasses 1530 along tilt axis 1585 to simulate differentframe tilt angles. Processing logic 1597 may be configured to drive thetilting mechanism to move eyeglasses 1530 along tilt axis 1585 withinput/output X1.

FIG. 15B illustrates an example dot target pattern 1571 that may bedriven onto display 1557 to generate a distortion map and/or a PSF mapof prescription lenses 1531A and 1531B. FIG. 15C illustrates an exampleslant edge target 1572 that may be driven onto display 1557 to generatean MTF map of prescription lenses 1531A and 1531B.

Processing logic 1597 may drive a particular image onto display 1557 andthen drive input/outputs X1/X2/X3 to coordinate capturing an array ofimage signals 1556 with eyeglasses 1530 being stepped through differentpositions with respect to display 1557. Optical sensor may capture animage signal 1556 at each different position. In this way, acharacterization procedure to generate a distortion mapping of each ofprescription lenses 1531A and 1531B can be acquired. Optical sensor 1555may be placed at an optical center of lens 1531A for a firstcharacterization procedure of lens 1531A and then placed at an opticalcenter of lens 1531B for a second characterization procedure of lens1531B. In some embodiments, optical sensor 1555 is moved with respect tolenses 1531A/1531B during the characterization procedure. Processinglogic 1597 is configured to output lens measurement data 1599 generatedby the image signals acquired during the characterization procedure oflenses 1531A and 1531B. Lens measurement data 1599 may include adistortion profile of lenses 1531A and 1531B, an IPD derived fromoptical centers of lenses 1531A and 1531B determined by thecharacterization procedure, and/or optical powers of lenses 1531A and1531B. The distortion profile may include at least one of a ModulationTransfer Function (MTF) or a point spread function (PSF) of theprescription lenses 1531A and 1531B.

FIG. 16 illustrates different frames of head mounted devices, inaccordance with aspects of the disclosure. Head mounted device such asAR HMDs may be provided to users in a variety of different styles andform factors and a user may select a form factor of a head mounteddevice based on size or style preferences. FIG. 16 illustrates headmounted devices 1610, 1620, 1630, and 1640 having correspondingoptical-mechanical profiles 1611, 1621, 1631, and 1641, respectively.Each optical-mechanical profile of the head mounted devices may specifythe dimensions of the frame and the size of the lenses, for example.

FIG. 17 illustrates a process 1700 of fabricating a prescription opticalelement for a selected head mounted device that may reduce a transitiontime experienced by a user switching between eyeglasses and the headmounted device, in accordance with aspects of the disclosure. The orderin which some or all of the process blocks appear in process 1700 shouldnot be deemed limiting. Rather, one of ordinary skill in the art havingthe benefit of the present disclosure will understand that some of theprocess blocks may be executed in a variety of orders not illustrated,or even in parallel.

In process block 1705, user lens data is received. The user lens data isassociated with prescription lenses worn by the user. The user lens datamay include 3D optical-mechanical fit profile 1117 or include useroptical profile 1137 when volumetric depth images of a user are capturedof the user wearing their eyeglasses. The user lens data may alsoinclude an interpupillary distance (IPD) between a first pupil of afirst eye of the user and a second pupil of a second eye of the userwhen volumetric depth images of a user are captured of the user wearingtheir eyeglasses. The user lens data may include lens measurement data1599 when prescription lenses of eyeglasses are analyzed without theuser wearing the eyeglasses. The user lens data may include an opticalpower of prescription lenses. The user lens data may include a basecurve of the prescription lenses.

In process block 1710, a selected optical-mechanical profile of aselected head mounted device is received. For example, if a user selectsframes having the style of head mounted device 1630, the selectedoptical-mechanical profile would be optical-mechanical profile 1631 thatcorresponds to head mounted device 1630. If volumetric depth images arecaptured with a user wearing the selected head mounted device, theselected optical-mechanical profile may include a mapping of a face ofthe user and the selected head mounted device worn by the user.

In process block 1715, a distortion profile based on the user lens dataand the selected optical-mechanical profile is generated. The distortionprofile includes a same see-through optical performance as theprescription lenses, in some embodiments. The distortion profile mayinclude at least one of a Modulation Transfer Function (MTF) or a pointspread function (PSF) of the prescription lenses.

In process block 1720, a prescription optical element (e.g. 1200) forthe selected head mounted device is fabricated based on the distortionprofile generated in process block 1715. The prescription opticalelement may include a plano-concave prescription optical layer such asplano-concave prescription optical layer 1210. Fabricating theprescription optical element for the selected head mounted deviceincludes three-dimensional (3D) printing a prescription optical layeronto an optical element (e.g. 1220), in an embodiment. The prescriptionoptical element may include a base curve (e.g. base curve 1227) that isdifferent than a base curve (e.g. 906) of the prescription lensesincluded in the lens user data.

Since example process 1700 receives user lens data associated with theuser's existing eyeglasses and the selected optical-mechanical profileof a head mounted device that the user has selected, the prescriptionoptical element that will go in the selected head mounted device can befabricated to closely match a distortion profile of the user's existingeyeglasses. Consequently, the existing eyeglasses and the head mounteddevice will have the same or similar distortion profiles and anytransition time for switching between the eyeglasses and the headmounted device can be reduced or eliminated.

FIG. 18 illustrates an example fabrication process 1800 of fabricating aprescription optical element for a selected head mounted device that mayreduce a transition time experienced by a user switching betweeneyeglasses and the head mounted device, in accordance with aspects ofthe disclosure. The order in which some or all of the process blocksappear in process 1800 should not be deemed limiting. Rather, one ofordinary skill in the art having the benefit of the present disclosurewill understand that some of the process blocks may be executed in avariety of orders not illustrated, or even in parallel.

In process block 1805, a distortion profile is received. The distortionprofile is based on user lens data and a selected optical-mechanicalprofile of a selected head mounted device. The user lens data isassociated with prescription lenses worn by the user. The distortionprofile may be the same as distortion profile generated in process block1715 of process 1700. The selected head mounted device is an AR HMD, insome embodiments.

The user lens data is associated with prescription lenses worn by theuser. The user lens data may include 3D optical-mechanical fit profile1117 or user optical profile 1137 when volumetric depth images of a userare captured of the user wearing their eyeglasses. The user lens datamay also include an interpupillary distance (IPD) between a first pupilof a first eye of the user and a second pupil of a second eye of theuser when volumetric depth images of a user are captured of the userwearing their eyeglasses. The user lens data may include lensmeasurement data 1599 when prescription lenses of eyeglasses areanalyzed without the user wearing the eyeglasses. The user lens data mayinclude an optical power of prescription lenses. The user lens data mayinclude a base curve of the prescription lenses.

In process block 1810, a portion of a prescription optical element isreceived. Optical element 1220 may be received as the portion of theprescription optical element, for example. The portion of theprescription optical element is for coupling into a frame of a selectedhead mounted device (e.g. head mounted devices 1610, 1620, 1630, or1640).

In process block 1815, a prescription optical layer (e.g. plano-concaveoptical layer 1210) is coupled to the portion (e.g. 1220) of theprescription optical element and the prescription optical layer is basedon the distortion profile received in process block 1805. Coupling aprescription optical layer to the portion of the prescription opticalelement to form the complete prescription optical element includes 3Dprinting the prescription optical layer onto the portion of theprescription optical element, in some embodiments. The completedprescription optical element may include a display layer (e.g. 1223)disposed between an eye-tracking layer (e.g. 1221) and a base curvelayer (e.g. 1225).

Fabrication process 1800 may be performed by a fabrication systemsimilar to system 1300 where processing logic similar to processinglogic 1391 receives the distortion profile and drives the lens shapingapparatus 1350 to fabricate a prescription optical layer (e.g. aplano-concave optical layer) based on the distortion profile.

FIGS. 19A-19C illustrate see-through light outputs from as-builtprescription optical elements and an example measured distortionprofile, in accordance with aspects of the disclosure. In FIG. 19A,measured distortion profile 1903 represents a measured distortionprofile of one or more prescription lenses. The measured distortionprofile 1903 may be included in lens measurement data 1599 measuringprescription lenses 1531A and 1531B, for example. Measured distortionprofile 1903 generates output light 1905 when illuminated by input light1901. As discussed above, prescription optical elements (e.g. 1200) canbe designed to have the same or similar distortion profile as measureddistortion profile 1903. Designing a prescription optical element tohave a same or similar distortion profile as measured distortion profile1903 may include modeling all of the layers of the prescription opticalelement in a commercially available optical modeling software.

In the example of FIG. 19B, the optical properties of layers 1210, 1221,1223, and 1225 may all be modeled such that the distortion profile ofprescription optical element 1200 is the same or similar to measureddistortion profile 1903 so that when prescription optical element 1200is illuminated by the same input light 1901, prescription opticalelement generates output light 1915 that is the same or similar tooutput light 1905 generated by measured distortion profile 1903.Similarly, FIG. 19C illustrates a prescription optical element 1950generating output light 1925 that is the same or similar to output light1905 generated by measured distortion profile 1903 when prescriptionoptical element 1950 is illuminated by the same input light 1901.Prescription optical element 1950 relies on plano-concave optical layer1960 to provide the optical power of prescription optical element ratherthan relying on a base curve layer (e.g. base curve layer 1225) combinedwith a plano-concave optical layer (e.g. 1210) to provide the opticalpower.

Once prescription optical elements such as prescription optical elements1200 and 1950 are fabricated, the as-built see-through distortionprofile for each prescription optical element can be characterized inthe manufacturing environment. In some aspects, the measured as-builtsee-through distortion profile of each prescription optical element isdigitally stored in lookup table or other data structure and stored foruse with the head mounted device that the prescription optical elementwill be paired with. The as-built see-through distortion profile maythen be accessed by the head mounted device to inform various featuresof the head mounted device such as eye-tracking systems or near-eyedisplay systems to improve the quality and/or efficiency those features.

Embodiments of the invention may include or be implemented inconjunction with an artificial reality system. Artificial reality is aform of reality that has been adjusted in some manner beforepresentation to a user, which may include, e.g., a virtual reality (VR),an augmented reality (AR), a mixed reality (MR), a hybrid reality, orsome combination and/or derivatives thereof. Artificial reality contentmay include completely generated content or generated content combinedwith captured (e.g., real-world) content. The artificial reality contentmay include video, audio, haptic feedback, or some combination thereof,and any of which may be presented in a single channel or in multiplechannels (such as stereo video that produces a three-dimensional effectto the viewer). Additionally, in some embodiments, artificial realitymay also be associated with applications, products, accessories,services, or some combination thereof, that are used to, e.g., createcontent in an artificial reality and/or are otherwise used in (e.g.,perform activities in) an artificial reality. The artificial realitysystem that provides the artificial reality content may be implementedon various platforms, including a head-mounted display (HMD) connectedto a host computer system, a standalone HMD, a mobile device orcomputing system, or any other hardware platform capable of providingartificial reality content to one or more viewers.

The term “processing logic” (e.g. 297, 397, 1197, 1391, 1597) in thisdisclosure may include one or more processors, microprocessors,multi-core processors, Application-specific integrated circuits (ASIC),and/or Field Programmable Gate Arrays (FPGAs) to execute operationsdisclosed herein. In some embodiments, memories (not illustrated) areintegrated into the processing logic to store instructions to executeoperations and/or store data. Processing logic may also include analogor digital circuitry to perform the operations in accordance withembodiments of the disclosure.

A “memory” or “memories” (e.g. 298, 398 and/or 1198) described in thisdisclosure may include one or more volatile or non-volatile memoryarchitectures. The “memory” or “memories” may be removable andnon-removable media implemented in any method or technology for storageof information such as computer-readable instructions, data structures,program modules, or other data. Example memory technologies may includeRAM, ROM, EEPROM, flash memory, CD-ROM, digital versatile disks (DVD),high-definition multimedia/data storage disks, or other optical storage,magnetic cassettes, magnetic tape, magnetic disk storage or othermagnetic storage devices, or any other non-transmission medium that canbe used to store information for access by a computing device.

A network may include any network or network system such as, but notlimited to, the following: a peer-to-peer network; a Local Area Network(LAN); a Wide Area Network (WAN); a public network, such as theInternet; a private network; a cellular network; a wireless network; awired network; a wireless and wired combination network; and a satellitenetwork.

Communication channels may include or be routed through one or morewired or wireless communication utilizing IEEE 802.11 protocols,BlueTooth, SPI (Serial Peripheral Interface), I²C (Inter-IntegratedCircuit), USB (Universal Serial Port), CAN (Controller Area Network),cellular data protocols (e.g. 3G, 4G, LTE, 5G), optical communicationnetworks, Internet Service Providers (ISPs), a peer-to-peer network, aLocal Area Network (LAN), a Wide Area Network (WAN), a public network(e.g. “the Internet”), a private network, a satellite network, orotherwise.

A computing device may include a desktop computer, a laptop computer, atablet, a phablet, a smartphone, a feature phone, a server computer, orotherwise. A server computer may be located remotely in a data center orbe stored locally.

The processes explained above are described in terms of computersoftware and hardware. The techniques described may constitutemachine-executable instructions embodied within a tangible ornon-transitory machine (e.g., computer) readable storage medium, thatwhen executed by a machine will cause the machine to perform theoperations described. Additionally, the processes may be embodied withinhardware, such as an application specific integrated circuit (“ASIC”) orotherwise.

A tangible non-transitory machine-readable storage medium includes anymechanism that provides (i.e., stores) information in a form accessibleby a machine (e.g., a computer, network device, personal digitalassistant, manufacturing tool, any device with a set of one or moreprocessors, etc.). For example, a machine-readable storage mediumincludes recordable/non-recordable media (e.g., read only memory (ROM),random access memory (RAM), magnetic disk storage media, optical storagemedia, flash memory devices, etc.).

The above description of illustrated embodiments of the invention,including what is described in the Abstract, is not intended to beexhaustive or to limit the invention to the precise forms disclosed.While specific embodiments of, and examples for, the invention aredescribed herein for illustrative purposes, various modifications arepossible within the scope of the invention, as those skilled in therelevant art will recognize.

These modifications can be made to the invention in light of the abovedetailed description. The terms used in the following claims should notbe construed to limit the invention to the specific embodimentsdisclosed in the specification. Rather, the scope of the invention is tobe determined entirely by the following claims, which are to beconstrued in accordance with established doctrines of claiminterpretation.

What is claimed is:
 1. A method comprising: receiving user lens dataassociated with prescription lenses worn by a user; receiving a selectedoptical-mechanical profile of a selected head mounted device; generatinga distortion profile based on the user lens data and the selectedoptical-mechanical profile, wherein the distortion profile includes atleast one of a Modulation Transfer Function (MTF) or a point spreadfunction (PSF) of the prescription lenses; and fabricating aprescription optical element for the selected head mounted device basedon the distortion profile.
 2. The method of claim 1, wherein theprescription optical element for the head mounted device includes aplano-concave prescription optical layer.
 3. The method of claim 2,wherein fabricating the prescription optical element includes bonding aplano-side of the plano-concave prescription optical layer to a planarsurface.
 4. The method of claim 3, wherein a plano-side of theplano-concave prescription optical layer is bonded to a planar surfaceof an illumination layer configured to illuminate an eyebox area withnon-visible light.
 5. The method of claim 1, wherein fabricating theprescription optical element for the selected head mounted deviceincludes three-dimensional (3D) printing a prescription optical layeronto an optical element.
 6. The method of claim 1, wherein fabricatingthe prescription optical element includes bonding a prescription opticallayer.
 7. The method of claim 6, wherein the prescription opticalelement includes a display layer and an eye-tracking layer and whereinthe prescription optical layer is on an eyeward side of the prescriptionoptical element.
 8. The method of claim 7, wherein the prescriptionoptical layer is a plano-concave lens.
 9. The method of claim 1, whereinthe prescription optical element includes a first base curve that isdifferent than a second base curve included in the lens user data. 10.The method of claim 1, wherein the user lens data includes an opticalpower of the prescription lenses worn by the user.
 11. The method ofclaim 10, wherein the user lens data includes a three-dimensional (3D)mapping of a face of the user and the prescription lenses worn by theuser.
 12. The method of claim 1, wherein the selected optical-mechanicalprofile of the selected head mounted device includes a three-dimensional(3D) mapping of a face of the user and the selected head mounted deviceworn by the user.
 13. The method of claim 1, wherein the user lens dataincludes an interpupillary distance (IPD) between a first pupil of afirst eye of the user and a second pupil of a second eye of the user.14. The method of claim 1, wherein the distortion profile includes asame optical performance as the prescription lenses.
 15. The method ofclaim 1, wherein the selected head mounted device is an augmentedreality (AR) head mounted display (HMD).
 16. A fabrication methodcomprising: receiving a distortion profile generated based on user lensdata of a user and a selected optical-mechanical profile of a selectedhead mounted device, wherein the user lens data is associated withprescription lenses worn by the user; receiving a portion of aprescription optical element for coupling into a frame of the selectedhead mounted device; and coupling a prescription optical layer to theportion of the prescription optical element, wherein the prescriptionoptical layer is based on the distortion profile, wherein theprescription optical element includes a display layer disposed betweenan eye-tracking layer and a base curve layer.
 17. The fabrication methodof claim 16, wherein coupling the prescription optical layer to theportion of the prescription optical element includes three-dimensional(3D) printing the prescription optical layer onto the portion of theprescription optical element.
 18. The fabrication method of claim 16,wherein the selected head mounted device is an augmented reality (AR)head mounted display (HMD).
 19. A method comprising: receiving user lensdata associated with prescription lenses worn by a user, wherein theuser lens data includes an optical power of the prescription lenses wornby the user, and wherein the user lens data includes a three-dimensional(3D) mapping of a face of the user and the prescription lenses worn bythe user; receiving a selected optical-mechanical profile of a selectedhead mounted device; generating a distortion profile based on the userlens data and the selected optical-mechanical profile; and fabricating aprescription optical element for the selected head mounted device basedon the distortion profile wherein the prescription optical elementincludes a display layer disposed between an eye-tracking layer and abase curve layer.